Custom field data types in Salesforce CRM:

When creating a custom field in Salesforce, the first step is to select the appropriate data type for the field. There are many different field types which allow the storage of records of various data values such as numbers, dates, percentages, and so on. The following table shows the data type.

  

Data Type	Description
Auto Number	A system-generated sequence number that uses a display format you define. The number is automatically incremented for each new record.
Formula	A read-only field that derives its value from a formula expression you define. The formula field is updated when any of the source fields change
Roll-Up Summary	A read-only field that displays the sum, minimum, or maximum value of a field in a related list or the record count of all records listed in a related list.
Lookup Relationship	Creates a relationship that links this object to another object. The relationship field allows users to click on a lookup icon to select a value from a popup list. The other object is the source of the values in the list.
Master-Detail Relationship	Creates a special type of parent-child relationship between this object (the child, or "detail") and another object (the parent, or "master") where: The relationship field is required on all detail records. The ownership and sharing of a detail record are determined by the master record. When a user deletes the master record, all detail records are deleted. You can create rollup summary fields on the master record to summarize the detail records. The relationship field allows users to click on a lookup icon to select a value from a popup list. The master object is the source of the values in the list.
Checkbox	Allows users to select a True (checked) or False (unchecked) value.
Currency	Allows users to enter a dollar or other currency amount and automatically formats the field as a currency amount. This can be useful if you export data to Excel or another spreadsheet.
Date	Allows users to enter a date or pick a date from a popup calendar.
Date/Time	Allows users to enter a date and time, or pick a date from a popup calendar. When users click a date in the popup, that date and the current time are entered into the Date/Time field.
Email	Allows users to enter an email address, which is validated to ensure proper format. If this field is specified for a contact or lead, users can choose the address when clicking Send an Email. Note that custom email addresses cannot be used for mass emails.
Geolocation	(Beta) Allows users to define locations.
Number	Allows users to enter any number. Leading zeros are removed.
Percent	Allows users to enter a percentage number, for example, '10' and automatically adds the percent sign to the number.
Phone	Allows users to enter any phone number. Automatically formats it as a phone number.
Picklist	Allows users to select a value from a list you define.
Picklist (Multi-Select)	Allows users to select multiple values from a list you define.
Text	Allows users to enter any combination of letters and numbers.
Text Area	Allows users to enter up to 255 characters on separate lines.
Text Area (Long)	Allows users to enter up to 131,072 characters on separate lines.
Text Area (Rich)	Allows users to enter formatted text, add images and links. Up to 131,072 characters on separate lines.
Text (Encrypted)	Allows users to enter any combination of letters and numbers and store them in encrypted form.
URL	Allows users to enter any valid website   address. When users click on the field, the URL will open in a separate browser window.

Some Basic Differences:

Question: What is the difference between SOQL and SOSL in Salesforce?

Answer: 

SOQL	SOSL
It’s a Salesforce Object Query Language.	It’s a Salesforce Object Search Language.
Using SOQL we can search only on one object at a time.	Using SOSL we can search on many objects at a time.
We can query on all fields of any data type.	We can query only on fields whose data type is text, phone and Email.
We can use SOQL in Triggers and Classes.	We can use SOSL in Classes but not in Triggers.

Question:  What Is the difference between Custom Settings and Custom Object?

 Answer: 

Question: What is a difference between data loader and import wizard in salesforce?

 Answer:  

Question: what is the difference between data import wizard pilot and import wizard?

 Answer:  

 

Question: What is the difference between actionFunction and actionSupport tags?

 Answer: 

	ActionSupport	ActionFunction
1)	Directly call action method without JavaScript.	Call action method from JavaScript with AJAX.
2)	It can be used to call action method on  single event.	It can be used to call action method on different event.
3)	It cannot be called from JavaScript function. It only invoke controller action methods from other Visualforce components.	It defines a new JavaScript function which can then be called from within a block of JavaScript code.

Question: How to Export data using data loader and what is the difference between Export and Export all

Export:
So for we seen insert,update and upsert. There are the data import to salesforce. Some times we need data from saleforce. So data Export is needed to get data.
Now follow the step by step how to do this.

1. Click on the data loader icon on the desktop.

 

2. Then click on Export.Select the object to export and it's automatically selects extract.csv file otherwise you can select a .csv file to save data.

3. Then click on next. Here write simple SOQL query to select the data.
Choose the query fields below is the fields to export and create the where clauses to your query below is the SOQL query to filter the data. We simply select it will generate the SOQL query below editor.

4. Then click finish and it's done.

Export All:
We know using data loader to export all the data, but what is this export all data. Export only exports the records from object. But Export all is export data from Object and Recycle bin also. This is a major difference between exports and export all operations.

Follow the same steps followed by export. But first selection of operation is Export All button OK.

Question: What is upsert and what is the difference between update and upsert?

Upsert: Using data loader insert operation to insert and update operation to update records. But what is this upsert. Upsert mean combination of Update and Insert. I know you have question mark in your face. Some time update old records and insert new records. Now Upsert is come in to the picture to full fill the both insert and update operations. Existing records will be updated and new records will be inserted.
The following steps explain Upsert records in to salesforce using apex data loader.
1. Open the data loader, Select the Upsert operation.

 

2. Select the Object to upsert and select the .csv file also.

 

3. Then map the fields properly.

 

4. Then Click on Next button. It will ask conformation. Click on OK. 

 

5. Operation success zero errors and success. That's it.

Question: How To Switch ON The Development Mode in Salesforce?

Enable Development Mode:

 
Name--> My Settings --> Personal--> Advanced User 

Details--> Edit --> Enable Development Mode Check box.

 

Then Click On Save. You Turned ON the Development mode. 

Question: What is difference between Master-Details and Lookup Relationship? 

Answer:

Master-Details Relationship	Lookup Relationship
Child records should be associated to parent.	Optional, child records need not be associated to a parent.
Cascade record deletion.	No Cascade record deletion.
Standard objects cannot be a detail object. (Child object)	No such restrictions.
The Master-Details Relationship, field is required on the page layout of the detail object.	Lookup field on child not necessarily required.
Roll-up summary fields can be created on the parent object.	Cannot be establishing here.
Detail record inherits the sharing and security setting of its master record.	No effect on security.

Thanks.....